Analysis of land suitability for the siting of inter-municipal landfills in the Cuitzeo Lake Basin, Mexico

This paper presents three spatial decision-support models (Boolean logic, binary evidence and overlapping index of multiple class maps) to perform a land suitability analysis for sanitary landfill siting. The study was carried out in the basin of Lake Cuitzeo, Mexico, with the objective of locating areas that comply with environmental regulations and with the inter-municipality criterion, i.e., that are accessible by at least two municipalities. Biophysical and socio-economic data were processed in a Geographic Information System (GIS). The three models differ in their complexity and restrictiveness. The Boolean logic model is easier to apply and more restrictive than the other two, because it is based on the assessment of single attributes. On the other hand, the binary data and overlapping index methods are relatively more complex because they require attribute weighting. The results showed that 23 of the 28 municipalities included in the basin have at least one area that was classified as highly suitable. The most suitable areas covered from 63.8 to 204.5 km(2) (from 1.5% to 5%), and they are not distributed homogeneously, but clustered around four main sites. The larger and most suitable of these sites is located in the central part of the basin, and it can be accessed by five of the most densely populated municipalities. The proposed approach represents a low-cost alternative to support a common spatial decision-making process in developing countries.     

Geological characterization and environmental implications of the placement of the Morelia Dump, Michoacán, Central Mexico

The landfill of Morelia, the capital city of the state of Michoacán in central-western Mexico, is located 12 km west of the city and has operated since 1997 without a structure engineered and designed to control the generation in situ of biogas and leachates. A geological evaluation of the landfill site is presented in this paper. The results indicate that the site lacks ideal impermeable subsurface strata. The subsurface strata consist of highly fractured basaltic lava flows (east-west fault and fracture system trend) and sand-size cineritic material with high permeability and porosity. Geochemical analysis of groundwater from Morelia's municipal aquifer shows a high concentration of heavy metals (Cd, Pb, As) exceeding the Mexican environmental regulations, along with the presence of some organic pollutants (phenols). Analyses of samples of the landfill's permanent leachate ponds show very high concentrations of the same contaminants. Samples were taken from the leachate pond and from nearby water-wells during the rainy season (summer 1997) and the dry season (spring 1997, 1998, and 1999). In all cases, the concentration of contaminants registered exceeded the standards for drinking water of the World Health Organization (American Public Health Association, American Water Works Association, and Water Pollution Control Federation, 2000). Some metal contaminants could be leaching directly from the landfill.     

Geological Characterization and Environmental Implications of the Placement of the Morelia Dump,Michoacán,Central Mexico

Abstract

The landfill of Morelia, the capital city of the state of Michoacán in central-western Mexico, is located 12 km west of the city and has operated since 1997 without a structure engineered and designed to control the generation in situ of biogas and leachates. A geological evaluation of the landfill site is presented in this paper. The results indicate that the site lacks ideal impermeable sub-surface strata. The subsurface strata consist of highly fractured basaltic lava flows (east-west fault and fracture system trend) and sand-size cineritic material with high permeability and porosity. Geochemical analysis of groundwater from Morelia’s municipal aquifer shows a high concentration of heavy metals (Cd, Pb, As) exceeding the Mexican environmental regulations, along with the presence of some organic pollutants (phenols). Analyses of samples of the landfill’s permanent leachate ponds show very high concentrations of the same contaminants. Samples were taken from the leachate pond and from nearby water-wells during the rainy season (summer 1997) and the dry season (spring 1997, 1998, and 1999). In all cases, the concentration of contaminants registered exceeded the standards for drinking water of the World Health Organization (American Public Health Association, American Water Works Association, and Water Pollution Control Federation, 2000). Some metal contaminants could be leaching directly from the landfill.     

Consumption patterns and household hazardous solid waste generation in an urban settlement in México

Mexico is currently facing a crisis in the waste management field. Some efforts have just commenced in urban and in rural settlements, e.g., conversion of open dumps into landfills, a relatively small composting culture, and implementation of source separation and plastic recycling strategies. Nonetheless, the high heterogeneity of components in the waste, many of these with hazardous properties, present the municipal collection services with serious problems, due to the risks to the health of the workers and to the impacts to the environment as a result of the inadequate disposition of these wastes. A generation study in the domestic sector was undertaken with the aim of finding out the composition and the generation rate of household hazardous waste (HHW) produced at residences. Simultaneously to the generation study, a socioeconomic survey was applied to determine the influence of income level on the production of HHW. Results from the solid waste generation analysis indicated that approximately 1.6% of the waste stream consists of HHW. Correspondingly, it was estimated that in Morelia, a total amount of 442ton/day of domestic waste are produced, including 7.1ton of HHW per day. Furthermore, the overall amount of HHW is not directly related to income level, although particular byproducts do correlate. However, an important difference was observed, as the brands and the presentation sizes of goods and products used in each socioeconomic stratum varied.     

Comparative analysis of hazardous household waste in two Mexican regions

Household hazardous waste (HHW) generation in two Mexican regions was examined, a northern region (bordering with the USA) and a central region. The aim of this work was to determine the dynamics of solid waste generation and to be able to compare the results of both regions, regarding consumption patterns and solid waste generation rates. In the northern region, household solid waste was analysed quantitatively. In order to perform this analysis, the population was categorized into three socioeconomic strata (lower, middle, upper). Waste characterization revealed the presence of products that give origin to household hazardous waste. In the northern region (Mexicali city), household hazardous waste comprised 3.7% of municipal solid waste, the largest categories in this fraction were home care products (29.2%), cleaning products (19.5%) and batteries and electronic equipment (15.7%). In the central region, HHW comprised 1.03% of municipal solid waste; the main categories in this fraction were represented by cleaning products (39%), self care products (27.3%), and insecticides (14.4%). In Mexicali, the socioeconomic study demonstrated that the production of HHW is independent of the income level. Furthermore, the composition of the solid waste stream in both regions suggested the influence of another set of variables such as local climate, migration patterns and marketing coverage. Further research is needed in order to establish the effect of low quantities of HHW upon the environment and public health.